hi,
maybe this "ancient" article by Brian Goetz may help you:
http://www.ibm.com/developerworks/library/j-jtp09238/index.html :)
cheers,
Kris
On Sat, Jan 18, 2014 at 8:39 AM, Ilya Obshadko <ilya.obsha...@gmail.com>wrote:
> Hello,
>
> I have implemented persistent session management in my application (using
> cookies and session IDs in the database). Everything works fine, but
> sometimes I see Hibernate errors "Batch update returned unexpected row
> count from update" when committing database changes after setting up a new
> session.
>
> It turns out that it happens when user starts a request and then quickly
> initiates reload of the same page. So I suppose this is a threading issue
> (one thread has already started creating session ID record, then user
> interrupts the connection and starts another request while the previous one
> hasn't been completed). I have implemented simple synchronization, but not
> yet sure if it's done correctly.
>
> So the question is: how do I synchronize method that creates the session?
>
> Currently it's implemented inside my authentication service:
>
> public void setupSessionForUser ( User user ) {
>
> synchronized ( this ) {
>
> user.clearSessions ();
>
>
>
> SessionToken newSessionToken = SessionToken.create ();
>
> user.addSessionToken ( newSessionToken );
>
> hibernateSession.save ( newSessionToken );
>
> asm.set ( User.class, (User) hibernateSession.merge ( user ) );
>
> cookies.writeCookieValue ( "authcookiename",
> newSessionToken.toString () );
>
> logger.info ( "set up new session {} for {}",
> newSessionToken.toString (), user.getEmail () );
>
> }
>
> }
>
> Is that correct to synchronize on *this*? Or should I synchronize on HTTP
> Session instance instead?
>
> Thanks in advance.
>
> --
> Ilya Obshadko
>
